Edwin t



(No Model.)

E. T. GREENPIELD;

TELEPHONE.

Patented Apr. 21, 1885.. v

N ETERS. Piwmmhy m hu. Waslunglon, D C

UNETE arts arENr FFiQi -t EDWIN T. GREENFIELD, OF NEYVYORK, -N. Y., ASSIGNOR OF ONE-HALF TO THE HOLMES BURGLAR ALARM TELEGRAPH COMPANY, OF SAME PLACE.

TELEPHONE.

EPECIFICATIQN forming part of Letters Patent No.316,260, dated April 21, 1885.

Application filed October 6, 1884.

(No model.) Patented in England March 1,-1883, No. 1,120, and in France March 6, 1883,

To rtZZ whom it may concern:

Be it known that I. EDWIN T. GRE NFIELD, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Telephones, of which the following is a specification.

The same has been patented to me in the following countries: Great Britain, No. 1,120,

dated March 1, 1883, and France, No. 154,110,

dated March 6, 18831 My invention consists in the combination, for a telephone-exchange system, of a number of subscribers service-lines and a multiple receiver located at a central officeand having a number of diaphragms and electromagnets and a sound-passage common to all.

It further consists in the combination, for a telephone-exchange system, of a number of subscribers service-lines and a multiple receiver located at a central office and having a number of diaphragms, and a corresponding number of electro-magnets arranged opposite the centers of the diaphragms and severally provided with a plurality of coils.

It'further consists in the combination, for a telephone-exchange system, of a number of subscribers service-lines and a multiple receiver at a central otfice supported over the place occupied by the operator, and having a sound passage terminating in a head piece provided with soundpassages adapted to lead tothe ears of the operator.

It further consists in the combination, for a 5 telephone-exchange system, of a number of subscribers service-lines and a multiple receiver at a central office supported over the place occupied by the operator, and having a head-piece for the operator secured with a 0 swiveling connection to the receiver.

In the accompanying drawings, Figure 1 is a side view of a multiple telephone-receiver embodying my improvement. Fig. 2 is a vertical section of the multiple receiver. Fig. 3

5 isa horizontal section of the multiple receiver. Fig. 4 is a transverse section of certain parts of the multiple receiver.

A designates wires forming part of the service-lines of subscribers of a-telephone-exchange. They extend to the electro-magnet belonging to one of the diaphiagms of the nmltiplereceiver. Preierably,tl1esubscribers telephoneinstruments will be normally connected 1n pairs orgroups with the multiple receiver. The multiple receiver issupported by rods or other suitable means, B, from a support'above a table provided with a switchboard, at which the operator sits. It com- I prises a numberoi' diaphragms, C, and appurtenances attached to a common body-piece, O. This body-piece has one vertical passage, 0', and. a number of radial passages-"0, communicating therewith. At the ends of these passages are chambers G, containing electro mugnets O and the diaphragms C. It will be seen that the electromagnets G are opposite the centers of the diaphragms O. The chambers O communicate with the passages, and the diaphragms are arranged close to the passages. Sounds emitted from any of the diaphragms will pass through the passages to the lower end of the vertical passage C. At the said lower end is a flexible tube, 0 which may be made of india-rubber and is connected to a head-piece, G. The stem of this head-piece is tubular, and the flexible tube has fastened to its lower end a gasket, a, which isconnected by a union coupling with the stem of the headpiece. In this way a swiveling connection is provided between the flexible tube and the head-piece.

The head-piece comprises branch pipes b, terminating in sections of flexible material 0, provided with ear-pieces d. Between the earpieces preferably extends a strip of flexible material.-such as metal or hard india-rubber, e-adapted to fit the head of the operator. The operator sits at the switch-board with this head-piece applied to his head, and hears any orders which maybe given tohim by the sub scribers. The flexible tube whereby the headpiece is connected to the vertical passage 0 and the swiveling connection of thehead-piece with the said flexibletube afford provision for motions of the head of the operator. The flexible terminal sections of the head-piece ent coils of wire.

conduce to the same result. The operator never needs to change his position to listen at the multiple receiver when it isth us arranged.

The electro-magnet belonging to each diaphragm is intended to have severah-as here shown, it hasthree-separate and independ- This feature of it may be seen best in Fig. 4. Each coil, preferably, has a pair of. subscribers wires connected to it; hence every one of the electro-magnets and its diaphragm in this example of my invention serves for six subscribers. coils are connected with binding screws on the head-piece of the multiple receiver, and to these biudiugscrews are secured the wires A. Attached to this head-piece is a drum, 0, which surrounds and incloses the body-piece O and the chamber 0*.

When the operator hears an order, helearns which subscriber is giving the order by the subscriber calling out his number. In such case the operator has merely to make the necessary connections to place the subscribers in communication. \Vhen the two subscribers are connected by the operator, they are notified ot' the fact that they are connected.

It will be seen that by my improvement I provide a multiple receiver which is at once simple and compact, and which will be supportedin position for use and will leave the operators hands free.

I do not wish to claim here anything which is shown in my Letters Patent No. 252,294, bearing date January 10, 1882, or which is shown in my Letters Patent No. 256,432, bearing date April 11, 1882.

The ends of these What I claim as myinvention, and desire to secure by Letters Patent, is-

1. For a telephone-exchange system, the combination of a number of subscribers servicelines and a multiple receiver located at a central office and having a number of diaphragms and electro-magnets and a soundpassage common to all, substantially as specified.

2. For a telephone-exchange system, the combination of a number of subscribers service-lines and a multiple receiver located at a central office having a. number of diaphragms and a corresponding number of electromagnets arranged opposite the centers of the diaphragms and severally provided with a plurality of coils, substantially as specified.

3; For a telephone-exchange system. the combination of a number of subscribers service-lines and a multiple receiver at a central otfice supported over the place occupied by the operator, and having a sound-passage terminatingin a head-piece provided with soundpassages leading to the ears of the operator, substantially as specified.

4. For a telephone exchange system, the combination of a number of subscribers service-lines and a multiple receiver at a central office supported over the place occupied by the operator, and having a head-piece for the operator secured with a swiveling connection to the receiver, substantially as specified.

1 E. T. GREEN FIELD.

Witnesses:

T. J. KEANE, WV. G. LIPsEY. 

